Solid state electronic calculators appeared during the 1960's as a smaller and quieter alternative to earlier electro-mechanical adding and calculating machines. In 1967, a team of Texas Instruments engineers led by Jack Kilby completed the development of its first prototype integrated circuit electronic calculator, which they called the “Cal-Tech,” generally regarded as the world's first “pocket” electronic calculator. It handled the four elementary arithmetic functions, was contained in a small rectangular box, weighed only 45 oz. and used a thermal printer to display results. Texas Instruments was awarded U.S. Pat. No. 3,819,921 on the results of this work.
Development of electronic calculators continued, resulting in ever smaller calculators with ever higher functionality. In 1975 Texas Instruments introduced its first programmable calculator, the SR-52. It had 224 program steps and 20 memory registers, as well as a built-in magnetic card reader. Further improvement to the programmable calculator has led to the development of what has come to be known as the graphing calculator. These handheld calculators combine small size, sophisticated mathematical capability, including the capacity to be programmed with algebraic functions in addition to mathematical operations, and a relatively large display screen, typically comprising a liquid crystal display (LCD), allowing a user to have entered functions be solved and displayed as graphs on the display screen.
The usefulness of handheld graphing calculators in a classroom setting for enhancing the educational experience in both mathematics and science has been widely recognized, and graphing calculators have been used in this way for years. Modern graphing calculators frequently are provided with the capability of being networked together. In today's classroom, such calculators can be networked together along with a teacher's station, which may itself be a graphing calculator, or may be a personal computer.
Such network configurations can greatly enhance the instructional benefits of graphing calculators. In fact, in many states graphing calculators are not only permitted, but are sometimes even required during exit (graduation) exams or end-of-course exams. Using such networked graphing calculators, teachers can teach students algebraic and higher functions which are embedded in hardware and/or firmware programs built into the calculator, software programs stored in the calculator in a BASIC-like language, as well as new software programs, called “Apps” and ASM programs, stored in the calculator, typically in assembly language and entered by the student, or entered by the teacher using the network connection. The knowledge of such functions and the use of the graphing calculator to manipulate them may then be tested during the exam, with the results of the student's work being uploaded to the teacher's station for evaluation and grading.
However, the expanded functionality of handheld programmable calculators which has done so much to enhance the teaching experience in the classroom carries with it a problem, especially in light of the use of such calculators during exams. Exactly because such calculators can be programmed by the student by the storing of Apps and of other information, the student may pre-load an App and/or additional information before an exam that gives the student an unfair advantage over other students. Additionally, a teacher may wish that the students not have available to them during an exam selected programs on the calculator, including Apps, that may have even been stored as part of the teaching experience. Because of this, some states, such as Texas and New York, require that programmable calculators be totally cleared of Apps and additional information prior to an exam in which such calculators are to be used.
Thus it can be seen that the programmable calculator is serving two different environments. One environment is the instructional environment, in which teachers want the students to have access to programs, Apps and other information that may be stored on the calculator, in order to help the student in their learning of math and science topics. The other environment is the testing environment, in which the students are being tested on what they have learned, and therefore may not be allowed to use the programs, Apps and additional information that assisted them with their learning.
It would therefore be desirable for teachers to have students have quick, easy access to programs, Apps and other information in their handheld programmable calculators during instruction, but then not available during exams, but then available again after exams. However, in the handheld calculator art today, the only way to remove programs, Apps and other information in preparation for an exam is to delete them from the calculator altogether. The removal of such items from the calculator takes relatively little time, involving a simple erase operation. However, the restoration of such items requires reloading every such item that was deleted. This can take up to thirty minutes, depending on how many Apps and programs, and how much additional information is being returned to the calculator. This puts a highly undesirable burden on the teacher.